arm64: dts: qcom: Add device tree for Xiaomi Redmi 2 (wingtech-wt88047)

arm64: dts: qcom: Add device tree for Xiaomi Redmi 2 (wingtech-wt88047)

The Xiaomi Redmi 2 is a MSM8916 smartphone that was made by Wingtech
(codename: wt88047). It's fairly similar to the other MSM8916 devices.

The device tree contains initial support for the Xiaomi Redmi 2 with:
  - UART (untested, probably available via some test points)
  - eMMC/SD card
  - Buttons
  - Vibrator
  - WiFi/Bluetooth (WCNSS)
  - USB

Note that the Xiaomi Redmi 2 is available in variants with different
names (e.g. Redmi 2 Prime, Redmi 2 Pro, ...). As far as I know the main
difference between those is the amount of RAM and supported LTE bands.
This difference is automatically handled by bootloader/modem firmware
so there is no need for separate device trees.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210712133735.318250-1-stephan@gerhold.net
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>